The present invention relates to a solid electrolytic capacitor and a method for manufacturing the same.
A typical solid electrolytic capacitor includes a sintered body formed by press forming and sintering powder of valve metal, such as niobium (Nb) and tantalum (Ta), together with an anode lead. The sintered body is then anodized to form a dielectric layer including mainly oxides on the surface of the sintered body. Subsequently, an electrolyte layer (e.g., manganese dioxide, polypyrrole, polythiophene, etc.) is formed on the dielectric layer. Lastly, a cathode layer (e.g., laminated film of carbon layer and silver paste layer) is formed on the electrolyte layer to obtain a capacitor element. Thereafter, an anode lead and an anode terminal (anode lead frame) are welded and connected together, the cathode layer and a cathode terminal (cathode lead frame) are connected together with a conductive adhesive, and a transfer process is carried out to perform molding and complete the solid electrolytic capacitor. This manufacturing method is described, for example, in Japanese Laid-Open Patent Publication No. 2006-186083.
In such a method of the related art for manufacturing a solid electrolytic capacitor, stress concentrates near the base of the anode lead during molding (i.e., when injecting mold resin into a mold). This may damage the dielectric layer near the base of the anode lead and thereby increase the leakage current of the solid electrolytic capacitor.